Elevated cerebrospinal fluid and plasma homocysteine levels in ALS.

Background: High cerebrospinal fluid (CSF) and plasma levels of homocysteine (HC) have been reported in certain neurodegenerative disorders, such as Alzheimer’s, Parkinson’s diseases and, recently, amyotrophic lateral sclerosis (ALS).Objectives: To assay the CSF and plasma levels of HC in ALS patients and controls, and to evaluate the relationship between HC levels and clinical variables of the disease.Methods: Cerebrospinal fluid from sixty-nine (M/F 1.87) and plasma from sixty-five ALS patients (M/F 1.83) were taken and stored at −80°C until use. Controls (CSF = 55; plasma = 67) were patients admitted to our hospital for neurological disorders with no known relationship to HC changes. CSF and plasma from ALS patients and controls were obtained as a necessary step of the diagnostic workup. HC levels in CSF and plasma were assayed using a high performance liquid chromatograph (HPLC) and a fluorimeter detector.Results: The median level of total HC in the CSF of ALS patients was 0.46 μM, significantly higher than that of the controls (0.24 μM, +91.6%, P < 0.001). A similar trend was observed when HC was assayed in plasma (ALS, 12.4 μM vs. controls, 7.26 μM, +70.8%, P < 0.001). The CSF and plasma HC levels showed no relationship with the disease progression, age at onset, and the site of onset.Conclusions: Homocysteine is a biochemical marker in ALS, and it might be related to the pathophysiology of the disease.